Side Chain Effects on Polymer Properties
Effect of Side Chains on Polymer Properties
Hydrogen as a Side Chain
In hydrogen polymers, the properties are determined by C-H bonds. Thus, these polymers are:
- Water-resistant
- Soluble in organic solvents
- Resistant to chemical attack
- Sensitive to free radical attack
Hydrogen as a side group does not provide any steric hindrance to the torsional mobility of the main chain. Therefore, such polymers have low glass transition temperatures. The small size of hydrogen favors the packing of chains; hence, the
Read MorePetroleum, Metallurgy, and Chemical Products: Uses and Impacts
Petroleum: Formation and Uses
Oil is a mixture of hydrogen and carbon (hydrocarbons) formed by the decomposition of the remains of marine animals and plants that were buried at the bottom of the sea, subjected to elevated temperatures and the action of bacteria for millions of years. It is a dark brown, oily liquid with a characteristic odor.
Fractions Obtained by Distillation:
- Refinery gas: Similar in composition to natural gas.
- Petrol: Used as a solvent and as fuel in spark-ignition engines.
- Kerosene:
Atomic Models and Chemical Bonding: A Comprehensive View
Atomic Models
Dalton Model
- Each element is composed of indivisible particles called atoms.
- In an element, all the atoms are identical.
- Atoms of different elements are all different.
- When atoms of more than one element combine, they form molecules. Compounds are made of molecules.
- In a chemical reaction, atoms are not created, destroyed, or changed into other types of atoms.
Thomson Model
Thomson based this model on his work with cathode rays. In this model, an atom consists of a positively charged jellylike
Read MoreCrude Oil, Hydrocarbons, and Chemical Processes
Crude Oil and Fractional Distillation
Crude oil is a complex mixture of hydrocarbons (compounds containing hydrogen and carbon only). Crude oil is separated by fractional distillation in a continuous process, taking off the samples at different levels from the fractionating column. The dissolved gases come out of the top, and the boiling points rise as one goes down the column.
- Refinery gases: Used for bottled gases such as gas, propane, butane
- Gasoline: Fuel for cars (petrol)
- Kerosene: Fuel for jet
Alkali, Alkaline Earth, Aluminum, Halogen, Oxygen, and Sulfur Properties
Element Representation
Alkali and Alkaline Earth Metals
Alkali and alkaline earth metals have low ionization potential (IP) and electron affinity (EA), meaning they easily lose electrons. They have increasing atomic radius (Z) down a column, higher density, and lower melting points.
Physical Properties: Good conductors of heat and electricity, low melting points, and are soft.
Chemical Properties: They are strong reducing agents, readily forming ionic compounds. They react with oxygen to form oxides
Read MoreUnderstanding Chemical Bonds: Types and Properties
Chemical Bonds: Types and Properties
In chemical bonds, atoms tend to bind to each other to form more complex entities, which make up substances.
Ionic Bonds
When an atom that is missing a few electrons in its valence shell is faced with another atom of low electronegativity, an electron transfer occurs. This is common between metals and nonmetals. The fundamental process of electron transfer results in what is known as an ionic network or crystal. In ionic compounds, we cannot speak of individual
Read More